Progressing with building up the left wing skeleton, the plan for today is to drill the rear spar to the wing ribs here on the left wing. To start I have the rear spar clamped in place to the inboard and outboard wing ribs.
On the inboard side I made a straight edge to give me way to check the dimension of the rear spar (left/right) to the inner most edge of the main wing spar. This dimension looks easy on paper but without getting myself this straight edge setup, I couldn’t figure out how else to work it.
Drilling the ribs is pretty straight forward. The way I ensured that all ribs were properly located was to start with getting the tip wing rib perfectly aligned at 90-degrees to the spars (both front and rear). That gave me a good starting point. From there I just measured the distance of the ribs along the main spar, and got that dimension set for the rib along the rear spar. Then clamped the rib in place. Before drilling, I then also double checked the measurement, and checked that the rib was straight vertically (not slanted left or right). When all that was good, then I drilled the ribs to the rear spar.
On a couple of the inboard ribs (ribs 1 – 5 area) I screwed up by pre-drilling the ribs. These ribs only have 2 rivets and are not the same spacing as the other outboard ribs (ribs 6 – 14). Because of that, I didn’t want to stop with my progress, as shown in the picture below, I figured out where the rivet holes needed to be located, predrilled the rib with the new location, and then drilled the rib to the spar.
To fix this little screwup, I’ll eventually cut off the rib flange and add a new one. It’s not the end of the world. Just be careful when you are at this part.
Also, while progressing out near the end of the rear spar wing root stiffener bars, keep an eye on your edge distance. I check this every now and then by using my calipers set with the minimum E.D.
When drilling the 5 inboard ribs, I located the ribs as I previously described above. However, for these, as I’m drilling through the stiffener bars, I chose to just mark the hole locations by lightly drilling with the hand drill, then removing the spar and doing the final drilling in the drill press to ensure better accuracy while drilling through the thicker material.
Another good building day. I’m happy with the progress! Please comment. I love to hear from my readers. Thanks again for coming along for this ride, you make my work worthwhile.